The mom's credit score is almost 700, and she talks very sincerely and looks eager to move in.3.A group of 4 college senior female students and a co-signer who is the father of one tenant. 

And add the 3rd room can be used as bedroom or den, but is big enough for a queen sized bed.And I'd add to the dog weight 50 lbs "adult" weight - just to cover the sneaky ones lying about the age of their dog.Maybe you can put in your search terms the name of the university, so when they do searches for rentals by such and such university, it will show up.  

I have some apartments rented to 2-3 adults, and when they want to renew I will offer to drop off a lease and then have them let me know once they've all signed it, then I will wing by and pick it up.  

Also 4 adults utilities are going to be much higher then a family of 4 more then likely, and if you ever wanted to sell the potential for a family to buy the home over multiple individuals is greater.

Also what do you guys do then there is 3-4 unrelated adults that want to rent the property, do you charge extra for lets say more than 2 adults?

Some states have a requirement that only so many unrelated adults can live in a unit, etc.If you put your criteria in the ad, nobody can later say you made up criteria because they were ___________________.  

Only the adults listed on the lease are.

Now, however, they have discovered that the 15 year old sister of one of the two adults named in the lease, has been staying there.  

I'm now at the point where I have two applicants that can move in for July and I'm having a tough time choosing between two of them.Application 1 (3 related + 1 friend) - application was submitted first ProsPlenty of income to pay - 5x+2 with great credit (>700)work with a friend who gave a good reference1 attended the same religious institution i did so I'm less inclined to think they would mess up the unit which could be naive 1 year of rental history with no issues paying a fairly higher renthigh job security (family business)Conshigher chance of short term rental - I'm basing this on their young age and the fact they could easily decide to move out on their own2 with bad credit (<600)Young - early twentiesbasement will need to be used as an additional bedroompotential parking issues (4 cars)"kiddish" rooms would need to be repaintedApplication 2 (1 adult + 4 kids)Proshigher chance of long term rental (>3 years) - I say this because the last two locations this person stayed for 3 and 4 years only to leave when the houses were soldfit to the house - in that the rooms are decorated "kiddish" now and don't need to be modified at all ie. repainted, etc)paid same rent for over 7 years w/no issuesCons43% of income to rentBad credit (<600)  - I'm told this is the result of issues with the absentee parentI should also say i have a relative who is a lawyer involved in real estate so he's prepared my lease and helped me out with what can be done legally etc.

I got was I said I wanted for it, and I really did get the one perfect buyer out there for my unit.Plus, come on,  You're an adult who made a decision knowing that you might NOT end up with a bidding war.